Charge forming devices such as carburetors are known to include a choke valve to facilitate starting a cold engine. The choke valve may be manually closed before attempts to start the engine, or the choke valve may be automatically momentarily closed during an attempt to start an engine, such as by pulling a starter cord. In some starting systems, the choke valve is actuated when a starter cord is pulled to start the engine whereupon the choke valve is closed during a portion of the starter cord stroke when there is greatest resistance on the cord, such as when a piston of the engine approaches and reaches top dead center. After the higher resistance portion of the starter cord stroke, the choke valve returns toward its open position under force of a return spring. Accordingly, the engine may initially start while the choke valve is momentarily closed, and then die out as the choke valve moves away from its closed position.